Polymer Chemistry Commons^™

Drug Delivery, Disulfide Crosslinked Hydrogel Coating For Polydimethylsiloxane (Pdms) Implant Materials, Paul A. Contos, Paul Anthony Contos

Master's Theses

Though polydimethylsiloxane (PDMS) is often used in medical devices due to its desirable mechanical properties and biocompatibility, its surface is often prone to bacterial adhesion. This is especially a problem for catheters, where bacteria can adhere and form biofilms that can in turn result in Urinary Tract Infections (UTI). In order to deter the presence of UTI causing bacteria on PDMS catheters, methods were developed to formulate a disulfide crosslinked hydrogel coating and create a methodology to allow adhesion to a PDMS substrate. The hydrogel coating discussed in this paper will be synthesized by chemically crosslinking stimuli-responsive vesicles, that carry …

Melts To Solutions: Structure, Dynamics, And Response Of Polyelectrolytes, Shalika Meedin

All Dissertations

The current research elucidates the changes in the structure and motion of polyelectrolytes as they are perturbed by solvents and shear flows. Polyelectrolytes are macromolecules whose backbone consists of long, predominantly hydrocarbon chains, substituted by ionizable groups, which tend to dissociate into ions in polar solvents. Their properties result from a delicate balance of elastic energy that arises from the polymeric backbone and electrostatic forces, which stem from the ionizable groups. Though polyelectrolytes have an immense potential to propel numerous technologies, from clean energy to drug delivery systems, understanding the delicate balance between the properties of the polymer backbone and …

Poly(Pyridinium Salt)S Containing 9,9-Bis(4- Aminophenyl)Fluorene Moieties With Various Organic Counterions Exhibiting Both Lyotropic Liquid-Crystalline And Light-Emitting Properties, Pradip K. Bhowmik, David King, Haesook Han, Andras F. Wacha, Matti Knaapila

Chemistry and Biochemistry Faculty Research

Main-chain conjugated and non-conjugated polyelectrolytes are an important class of materials that have many technological applications ranging from fire-retardant materials to carbon-nanotube composites, nonlinear optical materials, electrochromic materials for smart windows, and optical sensors for biomolecules. Here, we describe a series of poly(pyridinium salt)s-fluorene containing 9,9-bis(4-aminophenyl)fluorene moieties with various organic counterions that were synthesized using ring-transmutation polymerization and metathesis reactions, which are non-conjugated polyelectrolytes. Their chemical structures were characterized by Fourier transform infrared (FTIR), proton (1H) and fluorine 19 (19F) nuclear magnetic resonance (NMR) spectrometers, and elemental analysis. They exhibited polyelectrolytic behavior in dimethyl sulfoxide. Their lyotropic liquid-crystalline phases were …

Structural Color Pigments For Waterborne Coatings, Kyle William Liston

Master's Theses

Structural colors offer unique alternatives to conventional pigments, utilizing their microstructures to produce vibrant colors. These pigments offer an alternative source for colorants without the need for less environmentally friendly conventional pigments. In keeping with the sustainability approach, the use of waterborne coatings was chosen over solvent-based coatings. Here we report the synthesis of brushite platelet, silica supraball, and inverse opal pigments. Brushite platelets were produced through a condensation reaction, while silica supraballs were synthesized via the Stöber process and assembly was attempted using an oil-in-water emulsion. Inverse opal was produced through the templating of silica on poly(methyl methacrylate) (PMMA) …

Catalyzed Chemical Recycling Of Poly(Ethylene Terephthalate) For Enhanced Sustainability, Gilberto J. Hernandez-Leypon Jr.

Master's Theses

Plastics are ubiquitous in the production of consumer and industrial products; their chemical stability, low cost of production, and performance versatility make them the best option for many industries. Their inherent benefits, specifically durability, is the basis for the negative environmental impact of polymers. Improper containment of endof-life polymer products causes unintentional migration into the environment. The monomers for many common polymer types are also fossil fuel based further increasing the environmental impact of the plastic lifecycle. Recycling is a possible method of closing the loop of the plastic lifecycle. Currently most recycling is physical, thermally reprocessing used plastics into …

Myceli-Yum: Elucidating Structure-Property Relationships For Polymer Degradation By Mycelial Digestion, Jordan Scott Ford

Master's Theses

Since the industrial entrance of polymer plastic materials, plastic has become ubiquitous in both everyday use and waste. Due to inefficiencies and knowledge gaps, current recycling methods are not able to account for the high scale of plastic waste, resulting in the bulk of this waste being landfilled, mishandled, and deposited in the environment. Mycelium, the microorganism responsible for fruiting mushroom bodies and mold growth, holds potential to reduce plastic waste and can potentially be utilized as a method of industrial recycling. Following a drug-design approach, the active site of mycelial enzymes responsible for natural biopolymer degradation have been assessed …

Comparing Machine Learning Paired Optimization Strategies For Single-Component Waterborne Direct-To-Metal Coatings, Harvir S. Kalkat

Master's Theses

As R&D attempts to fine tune properties before production, the redesign and testing process can become highly iterative. The repetitive nature of formulating can be difficult to escape when relying on chemical intuition alone. To provide some guidance in this process, machine learning (ML) can leverage data from previous trials¹ to design suggestions for subsequent trials. Although ML capabilities have vastly expanded in the last few years, integration of ML into chemistry R&D and education has been slow. Unraveling the mystique of ML can help change what has been a slow embrace in the coatings industry. It is important …

Complementary Design Of Optical And Photochemical Systems, Joshua Plank

Chemistry Theses and Dissertations

The ability to manipulate chemical systems has been prized through history as the bridge between the macroscopic and microscopic worlds. As an example, the camera obscura has arguably existed since the earliest days of humanity; however, it was the discovery of early silver halide chemistry that lead to the ability to fix these images into the earliest photographs. In modern photolithography employed in electronics manufacturing, the primary resolution limits arise not from the chemistry of the molecules involved, but from the limits of the systems used to project light. Thus, as much as photochemistry advances, optical imaging and projection techniques …

The Effects Of Reprocessing, Post-Processing Conditions, And Environmental Exposure On The Physical Properties Of Post-Industrial And Post-Consumer Polyethylene, Grant M. Howard

Electronic Theses & Dissertations

THE EFFECTS OF REPROCESSING, POST-PROCESSING CONDITIONS, AND ENVIRONMENTAL EXPOSURE ON THE PHYSICAL PROPERTIES OF POST-INDUSTRIAL AND POST-CONSUMER POLYETHYLENE

An Abstract of the Thesis by

Grant Howard

Plastic pollution is a rapidly growing problem. Globally, millions of tons of plastic waste are produced, and that amount is projected to increase each year. To address this, recycling of commodity thermoplastics like polyethylene, polypropylene, and polyethylene terephthalate, have become a point of emphasis in industry. Companies have started to investigate the use of recycled plastics instead of virgin plastics in their products. The advantages of using recycled material are to receive tax breaks, …

Soybean Oil-Derived Acrylate/Methacrylate Ether For High Resolution Additive Manufacturing (3d Printing) Technology, Tanuj Patel

Electronic Theses & Dissertations

Additive Manufacturing is one of the rapidly developing techniques, as industries continue to explore new ways to create prototypes and end-use parts, one of the significant challenges that remains is the reliance on petroleum-based plastics for 3D printing, especially in the production of photocurable resins. that may be used to prototype complex structures and sophisticated geometries that are typically challenging to produce with conventional methods. Thus, replacing petroleum-based plastics with renewable resources is increasingly important for additive manufacturing (3D printing) of photocurable resins. The use of bio-based renewable resources in AM is a feasible alternative to traditional petroleum-based plastics. Henceforth, …

Epoxidized Castor Oil Based Thermosets With Reprocessable And Non Reprocessable Properties, Vaibhav Patel

Electronic Theses & Dissertations

Castor oil-based polymers have gained significant attention due to their renewable nature, low cost, and ease of processing, making them ideal for various applications, including biofuels and the petrochemical industry. Among these, epoxidized castor oil (ECO)-based thermosets have been extensively studied for their promising mechanical and thermal properties. This study focuses on recent advancements in ECO thermosets synthesized with 4,4-dithiodianiline (DTDA) which has aromatic disulfide bonds and 4,4-ditaminodiphenylmethane (DMPM) which has methylene bridge. FTIR spectroscopy confirmed the successful incorporation of epoxy functionalities into castor oil. The structure-reactivity relationship was examined through differential scanning calorimetry (DSC), which reveals that ECO_DMPM based …

Bio-Based Composites With Enhanced Mechanical Strength And Flame Retardancy, Riya Patel

Electronic Theses & Dissertations

Composites are versatile and useful in many fields, including aerospace, automotive, construction, and healthcare, due to their high mechanical strength. It is common practice to synthesize these materials using petroleum-based chemicals. Nonetheless, in the twenty-first century, scientists are more interested in using renewable resources to create composites. The greatest substitute for petroleum-based chemicals is vegetable oil. It has unsaturated double bonds that are modifiable chemically. In the present study, bio-polyol was synthesized using castor oil, an inedible vegetable oil. A ring-opening process was used to modify it and produce castor oil-based polyol. The synthesized castor oil-based polyol was characterized by …

Trade-Off Between Limonene & Geraniol-Based Reprocessable And Non-Reprocessable Epoxy Thermosets: Role Of Aliphatic Diamines In Polymer Networks Design, Priyankkumar Kanubhai Patel

Electronic Theses & Dissertations

The growing demand for sustainable materials, driven by environmental concerns and the rapid depletion of fossil fuels, has garnered significant attention in the fabrication of bio-based epoxy thermosets as renewable alternatives to petroleum-derived thermosetting polymers. The present study focuses on the synthesis and characterization of epoxy prepolymer resins derived from limonene and geraniol via a two-step process, followed by the fabrication of thermally cross-linked flexible epoxy thermoset films using various traditional aliphatic diamine curing agents, namely 1,2-ethylenediamine (EDA), 1,4-butylenediamine (BDA), and 1,6-hexamethylenediamine (HDA). Additionally, the incorporation of cystamine, a disulfide-containing diamine, enabled the formation of a covalent adaptable network through …

Effects Of Structure Of Mepegn Polymers On Hydroxide Conductivity In Anhydrous Anionic Exchange Membranes, Athan M. Gregory

Honors Theses

Anhydrous hydroxide ion (OH-) conducting polymer electrolytes composed of a 1-methyl-pyrrolidinium (1mp) head group linked to various MePEGn (n = 3, 7, 12) backbones were prepared. We have examined the structure of these anion exchange membranes to observe how the structure of the electrolyte affects the observed ionic conductivity. The structural parameters investigated were polymer length, viscosity, fractional free volume (FFV), and volume fraction of PEG (Vf,PEG), and each polymer varied in these properties. Through a comparison of the conductivity and structural parameters in the MePEGn-based anion electrolytes, we have shown that each of these structural properties weakly affects the …

Synthesis Of Single Chain Polymer Nanoparticle Networks By Reinitiating Raft Polymerization, Dallas Donovan

Honors Theses

Hydrogel materials, which are polymer networks comprised mostly of water, hold significant promise for biomedical applications due to their compatibility with biological systems. Conventional hydrogel materials are often brittle and weak, but most applications in biomedical systems require materials to be strong and tough. The topology of a polymer network dictates its mechanical properties. An important strategy for designing tougher hydrogels is the release of stored length, such as from the unfolding of polyprotein cross-linkers. Inspired by the success of the strategy, we report progress towards a fully synthetic design using single chain nanoparticles (SCNPs) into a hydrogel. SCNPs, which …

Linear Polydicyclopentadiene Copolymers: Synthesis And Thermal Properties, Connor Lewis

Honors Theses

No abstract provided.

Biomimetic Design Of Mechanochromic Single-Chain Nanoparticle Polymer Networks, Samuel Robinson

Honors Theses

Hydrogels are a class of polymer networks that show promise in many biomedical applications but are typically limited in use due to their brittle nature. Synthesizing hydrogel networks that are comparable to biological materials has long been an area of interest. In this study, we are working to create a polymer network inspired by the muscular protein, titin. Titin can unfold under mechanical tension, releasing stored length, making the muscle material extensible and durable. To mimic this behavior, we propose creating a polymer network with similar stored length using single chain nanoparticles (SCNPs) cross-linked with phenolphthalein (PP) and β-cyclodextrin (β-CD). …

Tailoring The Morphology Of Block Copolymers Via Solvent-Vapor Annealing, Bayleigh Madelin Loving

Honors Theses

Triblock polystyrene-polyisobutylene-polystyrene (PS-PIB-PS) copolymers have widespread applications from thermoplastic elastomers to protective coatings for ballistic applications. The incompatibility between the soft PIB and hard PS phases leads to phase separation and subsequent formation of morphological domains like lamellae and cylinders. The structures are stabilized by physical crosslinks, which can greatly improve the toughness of the triblock systems by preventing chain pullout during tensile deformation. We tailored the morphologies (achieving different morphologies with the same block copolymer) by changing the annealing conditions of the block copolymers. Solvent vapor annealing was used to selectively activate the mobility of a particular block, causing …

Development Of Porous Separators For Lithium-Ion Batteries Via 3d Printing And Thermally Induced Phase Separation, Abraham Enchinton

Open Access Theses & Dissertations

Additive manufacturing processes allow the development of custom-shape rechargeable batteries, but research in custom filaments for fused deposition modeling (FDM) of battery separators has remained limited until now. This study discusses the development and optimization of a composite thermoplastic filament feedstock to 3D print separator membranes. A number of post-processing steps - leveraging the thermally induced phase separation (TIPS) of the composite filament - are introduced in tandem with FDM to promote microporosity formation through the removal of the sacrificial diluent phase within 3D printed samples. Three distinct compositions of varying polymer/diluent ratios were developed and thoroughly investigated through thermogravimetric …

Mechanistic Investigation Of Ring-Opening Polymerization Of Polycaprolactone Using Tin(Ii) Catalysts: Ligand Effects And Biomedical Applications, Eva-Larue M. Barber

Honors Scholar Theses

This research explores the mechanistic aspects of ring-opening polymerization (ROP) of ε-caprolactone (CL) to produce polycaprolactone (PCL), a biodegradable polymer widely used in biomedical applications. The study investigates how light exposure and catalyst concentration influence polymerization efficiency, using tin(II) 2-ethylhexanoate [Sn(Oct)₂] as the catalyst in a non-polar toluene solvent at 90 °C. Reactions were conducted under either ambient light or black light bulb (BLB) illumination, with monomer-to-catalyst ratios of 1:1 and 200:1.

Proton nuclear magnetic resonance (¹H NMR) spectroscopy was used to analyze conversion efficiency by tracking the disappearance of monomer signals and appearance of characteristic PCL peaks. Results revealed …